In the liquid crystal panel industry, usually excimer laser annealing (ELA) process is a crystallization technique used to crystallize amorphous silicon (a-Si) to polycrystalline silicon. With respect to ELA process, gases used in a laser generator mainly include process gases, such as halogen gas, Xe gas, Ne gas, and/or He gas, with great variety and large usage quantity. Moreover, service life of the gases is usually three (3) to five (5) days, and the gas(es) in the apparatus must be replaced when its service time reaches this value even if the gas is not being used. Therefore, gas consumption is large, and a great operation cost occurs to the manufacturer.
An ELA apparatus mainly includes following elements/devices: a laser generator, an optical element, an annealing element, a controller, and a transmission element. The ELA apparatus are so large that it covers an area of tens of square meters to hundreds of square meters and has a weight of dozens of tons. The maintenance cost is high and risk rate is increased because of the complicated structures of the ELA apparatus.
Moreover, most of the components in an ELA apparatus are consumable components, for example, the continuous service life of a laser tube of a laser generator is only about half a year, but a price of the laser tube is above multi-million RMB. In addition, the prices of elements such as a gas pure element, a high voltage element, a pulse extent element, an optical module are all very expensive, and these elements to some extent belong to consumable components. Therefore, a great operation cost is brought due to frequently replace consumption components of an ELA apparatus.